Cervical and lumbar spinal interbody devices

ABSTRACT

Lumbar and cervical interbody or intervertebral devices for implantation between adjacent vertebrae of a spine and/or within intermediary canals of long bones are characterized by a body defining a superior end and an inferior end whose surfaces have serrations or teeth thereon forming anti-backout structures that allow implantation of the body but inhibit removal or backing out therefrom. The one-way structures may extend from the anterior end to the posterior end. The one-way structures may take different shapes but are always configured to allow insertion of the interbody device in an anterior-first manner while preventing and/or inhibiting the interbody device from backing out posteriorly. The various interbody devices may be further characterized by a body defining a cavity that is in communication with the superior and inferior ends of the body and at least one lateral side thereof via openings in the body. Undercuts are formed in the body about the adjacent the openings in order to support bony ingrowth within the void.

RELATED APPLICATIONS

This patent application claims the benefit of and/or priority to U.S.Provisional Patent Application Ser. No. 60/844,561 filed Sep. 14, 2006,entitled “Cervical and Lumbar Spinal Interbody and Cement RestrictorDevices” the entire contents of which is specifically incorporatedherein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to relates to interbody and/or cementrestrictor devices for implantation between a pair of adjacent vertebraein order to provide support to the vertebrae and/or promote bone fusionbetween the vertebrae or for implantation within the intermediary canalsof a femur, tibia or humerus.

2. Background Information

The disc between vertebrae of a human spine is sometimes damaged due todisease or injury, or may simply deteriorate due to age, disease, injuryor congenital defect. With others, the vertebrae may become compressedor otherwise damaged. In these and other cases the vertebrae can becometoo closely spaced anteriorly which causes an undesired abnormalcurvature of the spine with respect to lordosis or kyphosis.

Because of this, surgery may be utilized to place one or more spacers orinterbody devices between adjacent vertebrae to provide proper spacingof the vertebrae and which may also promote fusion between thevertebrae. When a device of this type is utilized for the purpose ofpromoting fusion, it is often termed a fusion cage or an intervertebralfusion device. When so utilized, bone or bone fusion material is oftenplaced about or in the interbody device(s) in order to promote growth ofthe bone between the adjacent vertebrae.

Interbody devices known as cement restrictors may also be used in bonessuch as the femur, tibia or humerus for the same or similar reasons asvertebral interbody devices. In these cases, the interbody device isimplanted within the intermediary canal of the particular bone.

When interbody devices are used, it is desirable for them to engage asmuch surface of the bone as possible to provide support to the bone andto thereby reduce the likelihood of subsidence of the device into thebone resulting from contact pressure of the interbody device againstbone surfaces. Subsidence can occur since part of the bone is somewhatspongy in nature, especially near the centers of the adjacent vertebrae.

In summation, the structure of interbody devices mainly functions tosupport the two adjacent vertebral surfaces, unless the interbody deviceis also used as a fusion cage within or around which to pack bone fusionmaterial, or to act as a cement restrictor within a long bone. Becauseit is also desirable in such structures to maintain weight and volume aslow as possible in order to make the device more compatible with thebody, it is also desirable to make the interbody device as small andlightweight as possible, while still maintaining strength.

Accordingly, there presently exists a need for improved interbodydevices.

SUMMARY OF THE INVENTION

The present invention provides lumbar and cervical interbody orintervertebral devices and/or long bone cement restrictor devices(collectively, interbody devices) for implantation between adjacentvertebrae of a spine and/or within intermediary canals of long bonessuch as the femur, tibia or humerus.

In accordance with an aspect of the present invention, the variousinterbody devices are characterized by a body defining a superior endand an inferior end whose surfaces have serrations or teeth thereon.These serrations or teeth allow easy implantation of the body butinhibit removal or backing out thereof after implantation and thus maybe considered one-way structures. In one form, the one-way structuresextend from an anterior end to a posterior end (i.e. one side to anotherof the body). The one-way structures may take different shapes but arealways configured to allow insertion of the interbody device in ananterior-first manner while preventing and/or inhibiting the interbodydevice from backing out posteriorly.

In accordance with an aspect of the present invention, the variousinterbody devices are further characterized by a body defining aninterior, cavity, void or the like that is in communication with thesuperior and inferior ends of the body and at least one lateral sidethereof via a hole, bore, aperture, fissure, outlet, opening or thelike. Undercuts are formed about the cavity adjacent the openings in thebody in order to support bony ingrowth within the cavity. The undercutsmay be configured in various manners depending on the overallconfiguration of the interbody device, the various voids formed in theinterbody device and/or passages formed in the interbody device thatprovide communication between one or more interior voids and theexterior of the interbody device.

Various shapes of interbody devices are disclosed for variousapplications and/or various positions along the spine or long bone. Theinterbody devices also may include one or more bores on the posteriorend of the body for aiding implantation. Some include markers on theupper and/or lower surfaces thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

The above mentioned and other features, advantages and objects of thisinvention, and the manner of attaining them, will become apparent andthe invention itself will be better understood by reference to thefollowing description of embodiments of the invention taken inconjunction with the accompanying drawings, wherein:

FIG. 1 is an anterior perspective view of a lumbar interbody devicefashioned in accordance with the present principles;

FIG. 2 is a posterior perspective view of the lumbar interbody device ofFIG. 1;

FIG. 3 is a superior plan view of the lumbar interbody device of FIG. 1,the anterior thereof facing to the left;

FIG. 4 is a side view of the lumbar interbody device of FIG. 1, theanterior thereof facing to the left;

FIG. 5 is an anterior plan view of the lumbar interbody device of FIG. 1taken along line 5-5 of FIG. 4;

FIG. 6 is a posterior plan view of the lumbar interbody device of FIG. 1taken along line 6-6 of FIG. 4;

FIG. 7 is an anterior perspective view of a lumbar interbody devicefashioned in accordance with the present principles;

FIG. 8 is a superior plan view of the lumbar interbody device of FIG. 7,the anterior thereof facing to the right;

FIG. 9 is an anterior plan view of the lumbar interbody device of FIG.7;

FIG. 10 is a sectional view of the lumbar interbody device of FIG. 7taken along line 10-10 of FIG. 9;

FIG. 11 is a posterior perspective view of a lumbar interbody devicefashioned in accordance with the present principles;

FIG. 12 is a superior plan view of the lumbar interbody device of FIG.11, the posterior thereof facing to the right;

FIG. 13 is a posterior plan view of the lumbar interbody device of FIG.11;

FIG. 14 is a side view of the lumbar interbody device of FIG. 11;

FIG. 15 is a sectional view of the lumbar interbody device of FIG. 11taken along line 15-15 of FIG. 12;

FIG. 16 is an anterior perspective view of a cervical interbody devicefashioned in accordance with the present principles;

FIG. 17 is a superior plan view of the cervical interbody device of FIG.16;

FIG. 18 is a sectional view of the cervical interbody device of FIG. 16taken along line 18-18 of FIG. 17;

FIG. 19 is a side view of the cervical interbody device of FIG. 16, theanterior thereof facing to the right;

FIG. 20 is an enlarged fragmentary view of an alternative serration ortooth design applicable to all of the present interbody devices;

FIG. 21 is a side perspective view of a cement restrictor/interbodydevice fashioned in accordance with the present principles;

FIG. 22 is a top plan view of the device of FIG. 21;

FIG. 23 is a left side view of the device of FIG. 21 as viewed from thetop plan view of FIG. 22;

FIG. 24 is a bottom view of the device of FIG. 21 as viewed from the topplan view of FIG. 22;

FIG. 25 is a sectional view of the device of FIG. 21 taken along line25-25 of FIG. 22;

FIG. 26 is an enlarged view of a portion of the sectional view of thedevice of FIG. 25 taken along line 26-26 thereof;

FIG. 27 is a combined top plan view and right side view thereof of onesize of the device of FIG. 21; and

FIG. 28 is a combined top plan view and right side view thereof of onesize of the device of FIG. 21.

Like reference numerals indicate the same or similar parts throughoutthe several figures.

Detail of the features, functions and/or configuration of the componentsdepicted in the various figures will now be presented. It should beappreciated that not all of the features of the components of thefigures may necessarily be described. Some of these non-discussedfeatures as well as discussed features are inherent from the figures.Other non-discussed features may be inherent in component geometryand/or configuration.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Referring to the Figures and in particular to FIGS. 1-6, there isdepicted an exemplary interbody device, generally designated 10,fashioned in accordance with the present principles. The interbodydevice 10 is preferably, but not necessarily, used as a lumbar interbodydevice and is defined by a generally rectangular body 12. The body 12 isfabricated from a bio-compatible material such as stainless steel,titanium, a titanium alloy, composite, polymer or the like. The body 12is sized to be received between adjacent vertebrae but to not extendbeyond the periphery of the vertebra. As such, the body 12 may befabricated in various sizes to accommodate various sizes of lumbarvertebrae. Moreover, the body 12 may be sized such that severalinterbody devices 10 may be situated as indicated above.

The body 12 has an anterior end 14 and a posterior end 16 each of whichis essentially flat, a superior side 22 having a plurality of serrationsor teeth 23, and an inferior side 24 having a plurality of serrations orteeth 25. It should be appreciated that since the body 12 issymmetrical, the superior side 22 may be the inferior side while theinferior side 24 may be the superior side, while maintaining theanterior end 14 and the posterior end 16. Therefore, the terms superiorand inferior are arbitrary. The superior side 22 and the inferior side24 are configured to abut the lower surface of an upper vertebra and theupper surface of a lower vertebra that is adjacent the upper vertebra,respectively. The body 12 also defines a first lateral side 18 and asecond lateral side 20. Again, it should be appreciated that thenomenclature first and second is arbitrary and thus interchangeable.

The interior of the body 12 is essentially hollow or has a cavitytherein that may be used to receive bone growth material and/or forallowing bony ingrowth therein. The interior cavity of the body 12communicates with the exterior of the body 12 via various openings inthe body 12. Particularly, the superior side 22 has a generally ovoidopening 56 and the inferior side 24 has a generally ovoid opening 58.The openings 56 and 58 are generally diametrically opposite one another.Moreover, the first lateral side 18 has a generally hourglass depressionor concavity 28 having a first essentially pear-shaped bore 30 on oneend of the depression 28 that is in communication with the interior ofthe body 12 and a second essentially pear-shaped bore 32 on the otherend of the depression 28 that is in communication with the interior ofthe body 12. The second lateral side 20 has a generally hourglassdepression or concavity 34 having a first essentially pear-shaped bore36 on one end of the depression 34 that is in communication with theinterior of the body 12 and a second essentially pear-shaped bore 38 onthe other end of the depression 34 that is in communication with theinterior of the body 12.

In accordance with an aspect of the present invention, the body 12 has afirst undercut 44 on the interior of the body 12 that extends in an arcfrom the bore 30 of the first lateral side 18 to the bore 34 of thesecond lateral side 20 and a second undercut 46 on the interior of thebody 12 that extends in an arc from the bore 32 of the first lateralside 18 to the bore 36 of the second lateral side 20. The arc of thefirst undercut 44 extends along the inner wall of the posterior end 16.The arc of the second undercut 46 extends along the inner wall of theanterior end 14.

In accordance with another aspect of the present invention, the superiorside 22 has a plurality of teeth or serrations 23 that extend from thefirst lateral side 18 to the second lateral side 20 and define pockets27 therebetween. As best seen in FIG. 4, the teeth 23 project towardsthe posterior end 16 of the body 12. This allows the insertion of theinterbody device 10 into a disc space (i.e. the space between adjacentvertebrae) in an anterior-first manner while preventing and/orinhibiting the interbody device 10 from backing out posteriorly.Likewise, the inferior side 24 has a plurality of teeth or serrations 25that extend from the first lateral side 18 to the second lateral side 20and define pockets 26 therebetween. As best seen in FIG. 4, the teeth 25project towards the posterior end 16 of the body 12. This allows theinsertion of the interbody device 10 into a disc space (i.e. the spacebetween adjacent vertebrae) in an anterior-first manner while preventingand/or inhibiting the interbody device 10 from backing out posteriorly.

The posterior end 16 also includes a center or main bore 50 thatprovides communication between the exterior of the body 12 and theinterior thereof. First and second side bores 52, 54 are also providedin the posterior end 16. These bores allow the use of a tool to insertthe interbody device 10 into the disc space and/or the packing of bonegrowth material into the interior of the body 12.

Referring now to FIGS. 7-10, there is depicted another exemplaryinterbody device, generally designated 100, fashioned in accordance withthe present principles. The interbody device 100 is preferably, but notnecessarily, used as a lumbar interbody device and is defined by agenerally rectangular body 112. The body 112 is fabricated from abio-compatible material such as stainless steel, titanium, a titaniumalloy, composite, polymer or the like. The body 112 is sized to bereceived between adjacent vertebrae but to not extend beyond theperiphery of the vertebra. As such, the body 112 may be fabricated invarious sizes to accommodate various sizes of lumbar vertebrae.Moreover, the body 112 may be sized such that several interbody devices100 may be situated as indicated above.

The body 112 has an anterior end 114 and a posterior end 116 each ofwhich is shown as being flat. These ends, however, may be other thanflat. For instance, the ends may be formed as an aggressive bulletshape. The body 112 also has a superior side 122 having a plurality ofserrations or teeth 123 and an inferior side 124 having a plurality ofserrations or teeth 125. It should be appreciated that since the body112 is symmetrical about a longitudinal axis thereof, the superior side122 may be the inferior side while the inferior side 124 may be thesuperior side, while maintaining the anterior end 114 and the posteriorend 116. Therefore, the terms superior and inferior are arbitrary. Thesuperior side 122 and the inferior side 124 are configured to abut thelower surface of an upper vertebra and the upper surface of a lowervertebra that is adjacent the upper vertebra, respectively. The body 112also defines a first lateral side 118 and a second lateral side 120.Again, it should be appreciated that the nomenclature first and secondis arbitrary and thus interchangeable.

The interior of the body 112 is essentially hollow or has a cavitytherein that may be used to receive bone growth material and/or forallowing bony ingrowth therein. The interior cavity of the body 112communicates with the exterior of the body 112 via various openings inthe body 112. Particularly, the superior side 122 has a generally ovoidopening 156 and the inferior side 124 has a generally ovoid opening 158.The openings 156 and 158 are generally diametrically opposite oneanother. Moreover, the first lateral side 118 has a first essentiallypear-shaped bore 130 that is in communication with the interior of thebody 112 and a second essentially pear-shaped bore 132 that is incommunication with the interior of the body 112. While not discernablein the figures, the second lateral side 120 has a first essentiallypear-shaped bore that is in communication with the interior of the body112 and a second essentially pear-shaped bore that is in communicationwith the interior of the body 112.

In accordance with an aspect of the present invention, the body 112 hasingrowth undercuts in the interior of the body 112. These undercuts aidin retaining the interbody device in its positioned placement once bonyingrowth occurs. Particularly, the body 112 has a first undercut 159 onthe interior of the body 112 that extends in an arc from the bore 130 ofthe first lateral side 118 to the bore (not shown) of the second lateralside 120 and a second undercut 161 on the interior of the body 112 thatextends in an arc from the bore 132 of the first lateral side 118 to thebore (not shown) of the second lateral side 120. The arc of the firstundercut 156 extends along the inner wall of the posterior end 116. Thearc of the second undercut 161 extends along the inner wall of theanterior end 114.

In accordance with another aspect of the present invention, the superiorside 122 has a plurality of teeth or serrations 123 that extend from thefirst lateral side 118 to the second lateral side 120 and define pockets126 therebetween. As best seen in FIG. 10, the teeth 126 project towardsthe posterior end 116 of the body 112. This allows the insertion of theinterbody device 100 into a disc space (i.e. the space between adjacentvertebrae) in an anterior-first manner while preventing and/orinhibiting the interbody device 100 from backing out posteriorly.Likewise, the inferior side 124 has a plurality of teeth or serrations125 that extend from the first lateral side 118 to the second lateralside 120 and define pockets 127 therebetween. As best seen in FIG. 10,the teeth 125 project towards the posterior end 116 of the body 112.This allows the insertion of the interbody device 100 into a disc space(i.e. the space between adjacent vertebrae) in an anterior-first mannerwhile preventing and/or inhibiting the interbody device 100 from backingout posteriorly.

Moreover, as best seen in FIG. 10, the superior side 122 and theinferior side 124 are not parallel or essentially parallel as are thesuperior and inferior sides of the interbody device 10. Rather, thesuperior and inferior sides 122, 124 are tapered inwardly towards eachother from the posterior end 116 to the anterior end 114. This structureprovides a significant increase in strength to the loading of theinterbody device.

The posterior end 116 also includes a center or main bore 117 thatprovides communication between the exterior of the body 112 and theinterior thereof. This bore allows the use of a tool to insert theinterbody device 100 into the disc space and/or the packing of bonegrowth material into the interior of the body 112.

Referring now to FIGS. 11-15, there is depicted another exemplaryinterbody device, generally designated 200, fashioned in accordance withthe present principles. The interbody device 200 is preferably, but notnecessarily, used as a lumbar interbody device and is defined by agenerally arc-shaped body 202. The body 202 is fabricated from abio-compatible material such as stainless steel, titanium, a titaniumalloy, composite, polymer or the like. The body 202 is sized to bereceived between adjacent vertebrae but to not extend beyond theperiphery of the vertebra. As such, the body 202 may be fabricated invarious sizes to accommodate various sizes of lumbar vertebrae.Moreover, the body 202 may be sized such that several interbody devices200 may be situated as indicated above. The body 202 is sized to bereceived between adjacent vertebrae but to not extend beyond theperiphery of the vertebra. As such, the body 202 may be fabricated invarious sizes to accommodate various sizes of lumbar vertebrae.Moreover, the body 202 may be sized such that several interbody devices200 may be situated as indicated above.

The body 202 has an anterior end 214 and a posterior end 216, theanterior end of which is arced and the posterior end 216 of which isrounded. The body 202 also has a superior side 222 having a plurality ofserrations or teeth 223 and an inferior side 224 having a plurality ofserrations or teeth 225. The superior side 222 and the inferior side 224are configured to abut the lower surface of an upper vertebra and theupper surface of a lower vertebra that is adjacent the upper vertebra,respectively. The body 202 also defines a first lateral side 216 and asecond lateral side 218. Again, it should be appreciated that thenomenclature first and second is arbitrary and thus interchangeable.

The body 202 has a first and second hollow or cavity therein that may beused to receive bone growth material and/or for allowing bony ingrowththerein. The first and second cavities communicate with the exterior ofthe body 202 via various openings in the body 202. Particularly, thesuperior side 222 has a first generally oval opening 226 and a secondgeneral oval opening 228. The inferior side 224 has a first generallyoval opening (not seen) and a second generally oval opening (not seen).The oval openings are generally diametrically opposite one another.Moreover, the first lateral side 216 has a first essentially pear-shapedbore 230 that is in communication with the first cavity of the body 202and a second essentially pear-shaped bore 232 that is in communicationwith the second cavity of the body 202. While not discernable in thefigures, the second lateral side 218 has a first essentially pear-shapedbore (not seen) that is in communication with the second cavity of thebody 202 and a second essentially pear-shaped bore (not seen) that is incommunication with the second cavity of the body 202.

In accordance with an aspect of the present invention, the body 202 hasingrowth undercuts in the interior of the body 202. These undercuts aidin retaining the interbody device in its positioned placement once bonyingrowth occurs. Particularly, the body 202 has a first undercut 226 inthe first cavity of the body 202 that extends in an arc and a secondundercut 228 in the second cavity of the body 202 that extends in anarc. The arc of the first undercut 226 extends along the inner wall ofthe anterior end 214, while the arc of the second undercut 228 extendsalong the inner wall of the posterior end 216.

In accordance with another aspect of the present invention, the superiorside 222 has a plurality of teeth or serrations 223 that extend from thefirst lateral side 216 to the second lateral side 218, while theinferior side 224 has a plurality of teeth or serrations 225 that extendfrom the first lateral side 216 to the second lateral side 218. As bestseen in FIG. 15, the teeth 223 and 225 project upwards from the body 202and are generally evenly spaced.

Moreover, as best seen in FIG. 12, first and second lateral sides 216,218 are curved. This bowing provides a significant increase in strengthto the loading of the part.

The posterior end 214 also includes a center or main bore 234 and firstand second side bores 236 and 238 are also provided in the posterior end16. These bores allow the use of a tool to insert the interbody device200 into the disc space.

Referring now to FIGS. 16-19, there is depicted another exemplaryinterbody device, generally designated 300, fashioned in accordance withthe present principles. The interbody device 300 is preferably, but notnecessarily, used as a cervical interbody device and is defined by agenerally trapezoidal body 302. The body 302 is fabricated from abio-compatible material such as stainless steel, titanium, a titaniumalloy, composite, polymer or the like. The body 302 is sized to bereceived between adjacent vertebrae but to not extend beyond theperiphery of the vertebra. As such, the body 302 may be fabricated invarious sizes to accommodate various sizes of cervical vertebrae.

The body 302 has an anterior end 312 and a posterior end 314, theanterior end 312 being essentially flat while the posterior end 314 isslightly curved. The body 302 also has a superior side 320 and aninferior side 322. It should be appreciated that since the body 302 issymmetrical about a longitudinal axis, the superior side may be theinferior side while the inferior side may be the superior side, whilemaintaining the anterior end 312 and the posterior end 314. Therefore,the terms superior and inferior are arbitrary. The superior side 320 andthe inferior side 322 are configured to abut the lower surface of anupper vertebra and the upper surface of a lower vertebra that isadjacent the upper vertebra, respectively. The body 302 also defines afirst lateral side 316 and a second lateral side 308. Again, it shouldbe appreciated that the nomenclature first and second is arbitrary andthus interchangeable.

The interior of the body 302 is essentially hollow or has a cavitytherein that may be used to receive bone growth material and/or forallowing bony ingrowth therein. The interior cavity of the body 302communicates with the exterior of the body 302 via various openings inthe body 302. Particularly, the superior side 320 has a generally ovoidopening 326 and the inferior side 322 has a generally ovoid opening (notseen) in like manner to the ovoid opening 326. The openings aregenerally diametrically opposite one another.

In accordance with an aspect of the present invention, the body 302 hasingrowth undercuts in the interior of the body 302. These undercuts aidin retaining the interbody device in its positioned placement once bonyingrowth occurs. Particularly, the body 302 has an undercut 330 in theinterior of the body 302 that extends in an arc. In accordance withanother aspect of the present invention, the superior side 320 has aplurality of teeth or serrations 321 that extend from the first lateralside 318 to the second lateral side 320 and define pockets therebetween.As best seen in FIG. 19, the teeth 321 project towards the posterior end314 of the body 302. This allows the insertion of the interbody device300 into a disc space (i.e. the space between adjacent vertebrae) in ananterior-first manner while preventing and/or inhibiting the interbodydevice 300 from backing out posteriorly. Likewise, the inferior side 322has a plurality of teeth or serrations 323 that extend from the firstlateral side 318 to the second lateral side 320 and define pocketstherebetween. As best seen in FIG. 19, the teeth 323 project towards theposterior end 314 of the body 302. This allows the insertion of theinterbody device 300 into a disc space (i.e. the space between adjacentvertebrae) in an anterior-first manner while preventing and/orinhibiting the interbody device 300 from backing out posteriorly.

The posterior end 314 also includes a center or main bore 328 thatprovides communication between the exterior of the body 302 and theinterior thereof. This bore allows the use of a tool to insert theinterbody device 302 into the disc space and/or the packing of bonegrowth material into the interior of the body 302.

Also, it should be appreciated that since the anterior end 312 issmaller in length than the posterior end 314, the first and secondlateral sides 316 and 318 are not parallel to one another. This providesa significant increase in strength to the loading of the part.

FIG. 20 depicts a fragmentary view of an alternative embodiment ofserrations or teeth applicable to the various interbody devicesdescribed herein. Particularly, an interbody device body 400 includesteeth or serrations 402 on an inferior and superior surface 401 thatface toward the posterior of the interbody device. The teeth 402 definerounded undercuts 404 therein.

Referring now to FIGS. 21-26, there is depicted another exemplaryinterbody device, generally designated 500, fashioned in accordance withthe present principles. The interbody device 500 may be used as acervical or lumbar interbody device and is defined by a generally ovoidbody 502. The body 502 is fabricated from a bio-compatible material suchas stainless steel, titanium, a titanium alloy, composite, polymer orthe like. The body 502 is sized to be received between adjacentvertebrae but to not extend beyond the periphery of the vertebra. Assuch, the body 502 may be fabricated in various sizes to accommodatevarious sizes of cervical vertebrae. This is represented in FIGS. 27 and28.

Particularly, FIG. 27 depicts one size of the interbody device 500designated 500 a having the same configuration as the interbody device500 but with the letter designation “a” after corresponding numericalparts thereof. FIG. 27 shows a top plan view of the interbody device 500a on the left side of the figure, and a right side view of the interbodydevice 500 a relative to the top plan view on the right side of thefigure. FIG. 28 depicts another size of the interbody device 500designated 500 b having the same configuration as the interbody device500 but with the letter designation “b” after corresponding numericalparts thereof. FIG. 28 shows a top plan view of the interbody device 500b on the left side of the figure, and a right side view of the interbodydevice 500 b relative to the top plan view on the right side of thefigure.

Referring back to FIGS. 21-26, the body 502 has an anterior end 512 anda posterior end 514, the anterior end 512 being essentially curved buttruncated (flat) at the peak thereof, with the posterior end 514 beingalso curved. The body 502 also has a superior side 520 and an inferiorside 522. It should be appreciated that since the body 502 issymmetrical about a longitudinal axis, the superior side may be theinferior side while the inferior side may be the superior side, whilemaintaining the anterior end 512 and the posterior end 514. Therefore,the terms superior and inferior are arbitrary.

The superior side 520 and the inferior side 522 are configured to abutthe lower surface of an upper vertebra and the upper surface of a lowervertebra that is adjacent the upper vertebra, respectively. The body 502also defines a first lateral side 516 and a second lateral side 518.Again, it should be appreciated that the nomenclature first and secondis arbitrary and thus interchangeable.

The interior of the body 502 is essentially hollow or has a cavity 526therein that may be used to receive bone growth material and/or forallowing bony ingrowth therein. The interior cavity 526 of the body 502communicates with the exterior of the body 502 via other variousopenings in the body 502.

Particularly, the posterior end 514 has a bore 528 that extends from theexterior of the body 502 to the cavity 526. The first lateral side 516has a bore 530 that extends from the exterior of the body 502 to thecavity 516. A bore 532 is situated at the transition between theposterior end 514 and the first lateral side 516 that likewise extendsfrom the exterior of the body 502 to the cavity 516.

In accordance with an aspect of the present invention, the superior side520 has a plurality of teeth or serrations 521 that extend from thefirst lateral side 516 to the second lateral side 518, but between aflat 540 on the superior side 520 proximate the posterior end 514 to ataper 536 on the superior side 520 proximate the anterior end 512. Theteeth 521 project towards the posterior end 514 of the body 502. Thisallows the insertion of the interbody device 500 into a disc space (i.e.the space between adjacent vertebrae) in an anterior-first manner whilepreventing and/or inhibiting the interbody device 500 from backing outposteriorly. Likewise, the inferior side 522 has a plurality of teeth orserrations 523 that extend from the first lateral side 516 to the secondlateral side 518, but between a flat 542 on the inferior side 522proximate the posterior end 514 to a taper 538 on the inferior side 522proximate the anterior end 512. The teeth 523 project towards theposterior end 514 of the body 502. This allows the insertion of theinterbody device 500 into a disc space (i.e. the space between adjacentvertebrae) in an anterior-first manner while preventing and/orinhibiting the interbody device 500 from backing out posteriorly.

FIG. 26 depicts a fragmentary view of the serrations or teeth 523 of theinterbody device 500. The teeth or serrations 523 define rounded troughs554 between flats 550 and tapers 552. The teeth or serrations 523 facetoward the posterior of the interbody device.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, the same is to be considered asillustrative and not restrictive in character, it being understood thatonly preferred embodiments have been shown and described and that allchanges and modifications that come within the spirit of the inventionare desired to be protected.

What is claimed is:
 1. An implant comprising: a body having alongitudinal axis and defining a first lateral side, a second lateralside, a superior side, and an inferior side, wherein an outer surface ofthe first lateral side includes a first depression with two enlargedends, and an outer surface of the second lateral side includes a seconddepression with two enlarged ends; first serrations formed on thesuperior side and extending from the first lateral side to the secondlateral side, the first serrations configured to allow implantation intoa space in a first direction but inhibit backing out of the space in asecond direction generally opposite of the first direction; secondserrations formed on the inferior side and extending from the firstlateral side to the second lateral side, the second serrationsconfigured to allow implantation into a space in the first direction butinhibit backing out of the space in the second direction; a cavityformed within the body and defined by an interior surface of the body; afirst opening formed in the superior side of the body and incommunication with the cavity; and a second opening formed in theinferior side of the body and in communication with the cavity; a firstbore formed in the first lateral side and in communication with thecavity and the first depression; a second bore formed in the secondlateral side and in communication with the cavity and the seconddepression; a groove formed in the interior surface of the cavity, thegroove centrally located along the longitudinal axis adjacent at leastone of the first opening and the second opening and extending betweenthe interior surface of the first lateral side and the interior surfaceof the second lateral side such that the first bore and the second borepass therethrough wherein the first bore passes through one of theenlarged ends of the first depression and into the groove, and thesecond bore passes through one of the enlarged ends of the seconddepression and into the groove.
 2. The implant of claim 1, wherein thefirst bore is pear-shaped and the second bore is pear-shaped.
 3. Theimplant of claim 1, wherein the first and second serrations each projecttowards a common direction of the body.
 4. The implant of claim 3,wherein the common direction is toward a posterior end of the body. 5.The implant of claim 1, wherein the implant comprises one of a lumbar,cervical and long bone implant.
 6. The implant of claim 1, wherein thebody is rectangular.
 7. An implant comprising: a body defining asuperior side, an inferior side, a first lateral side, and a secondlateral side, the first lateral side having an outer surface with afirst depression, wherein the first depression includes a first end witha first width, a second end with a second width, and a middle having athird width narrower than the first width and second width; wherein thesecond lateral side includes a second depression; a cavity formed withinthe body and defined by an interior surface of the body; a first boreformed in the first lateral side, the first bore in communication withthe cavity and the first end of the first depression; a second boreformed in the second lateral side, the second bore in communication withthe cavity; a first groove formed in the interior surface of the cavity,the groove extending between the interior surface of the first lateralside and the interior surface of the second lateral side such that thefirst bore and the second bore pass therethrough; and wherein the firstbore extends through the first lateral side between the first end of thefirst depression and the first groove; wherein the second depressionincludes a first end with a first width, a second end with a secondwidth, and a middle having a third width narrower than the first widthand the second width; and wherein the second bore extends through thesecond lateral side between the first end of the second depression andthe first groove.
 8. The implant of claim 7, wherein the implantcomprises one of a lumbar, cervical and long bone implant.
 9. Theimplant of claim 7, wherein the body is rectangular.
 10. An implantcomprising: a body defining a superior side, an inferior side, a firstlateral side, and a second lateral side; first serrations formed on thesuperior side, the first serrations configured to allow implantation butinhibit backing out of the body; second serrations formed on theinferior side, the second serrations configured to allow implantationbut inhibit backing out of the body; an internal cavity formed withinthe interior of the body and defined by an interior surface of the body;a first opening formed in the superior side of the body and incommunication with the cavity; a second opening formed in the inferiorside of the body and in communication with the cavity; a depressionhaving a first enlarged end, a second enlarged end; a first bore formedin the first lateral side, the first bore in communication with thecavity; a second bore formed in the first lateral side, the second borein communication with the cavity; a first groove formed in the interiorsurface of the cavity; and a second groove formed in the interiorsurface of the cavity; wherein the first bore passes through the firstenlarged end of the depression and into the first groove, and the secondbore passes through the second enlarged end of the depression and intothe second groove.
 11. The implant of claim 10, wherein the first andsecond serrations each extend from the first lateral side to the secondlateral side.
 12. The implant of claim 10, wherein the first and secondserrations each project towards a common end of the body.
 13. Theimplant of claim 12, wherein the common end is toward a posterior end ofthe body.
 14. The implant of claim 10, wherein the implant comprises oneof a lumbar, cervical and long bone implant.
 15. The implant of claim10, wherein the body is rectangular.